1. Field of the Invention
The present invention relates to an ink-jet recording apparatus including an ink-jet head for ejecting ink droplets onto a record medium.
2. Description of Related Art
A plotter is known that performs recording with a pen that is moved by pulling via a belt a carriage mounted with the pen. Supporting the carriage by two guide rails is disclosed in Japanese Patent No. 2797637 as a technique for reciprocating the carriage in one direction in such a plotter. Application of this technique to a serial printing-type ink-jet printer results in a structure in which the carriage mounted with an ink-jet head is supported by two guide rods and simultaneously reciprocates along the guide rails. In this case, the distance from the ink ejection surface of the ink-jet head to the record medium carrying surface is invariable.
However, a record medium for use in the ink-jet printer may have various thicknesses. Therefore, the distance from the ink ejection surface to the record medium surface confronting the ink ejection surface varies depending on the thickness of a record medium. For this reason, when record media having different thickness are used, the printing quality changes depending on the thickness of the printed medium, leading to unstable printing quality.